/*    					W3C Sample Code Library libwww Accessing URIs!  Accessing URIs!*//***	(c) COPYRIGHT MIT 1995.**	Please first read the full copyright statement in the file COPYRIGH.*//*This module is the application interface module to theRequest class. It contains a lot of methods forloading URIs and also for uploading URIs using PUT orPOST, for example. You can use the Request class directly butthis module makes it easier to use by providing a lot of small request functionsusing the Request class in different ways. It contains help functions foraccessing documents and for uploading documents to a remote server.This module contains functions for handling all HTTP/1.1 methods:      GET Requests      	 	       o 	 	Various GET requests including specialized functions like	loading a rule file, etc.      o 	 	Search requests based on the GET method      o 	 	Formdata requests based on the GET method    	       PUT Requests      	 	       o 	 	Save a document from memory ASIS using PUT      o 	 	Save a structured document from memory using PUT      o 	 	Save any URI (FTP, HTTP, local disk) using PUT    	       POST Requests      	 	       o 	 	Post Formdata to a remote HTTP server      o 	 	Post a document from memory ASIS to a remote HTTP	server    	       HEAD, DELETE, OPTIONS, and TRACE requests      	 	       o 	 	Get metainformation about a document using HEAD requests      o 	 	Delete documents based on the DELETE method      o 	 	Get information about the features supoprted by a resource	using OPTIONS      o 	 	Trace a request using the TRACE method    	 Furthermore, it contains a few access methods for handlingincoming requests - in orther words acting as a server. Although libwwwis primarily for clients, it is in fact symmetric in that it can handle bothclient requests and server requests.This module is implemented by HTAccess.c, and itis a part of the  W3C Sample CodeLibrary.*/#ifndef HTACCESS_H#define HTACCESS_H#include "HTReq.h"#include "HTAnchor.h"/*.  Load a Document (Method = GET).URIs can be accesses using a character string, for example"http://www.w3.org" or it can be accessed by using the libwwwrepresentation of a URI called an Anchor object.Note that we call all objects accessible through URIs for documents- this is a notion we have inherited from the hypertext world.(  Load a Document from Absolute URI)Request a document referencd by an absolute URI. The output from therequest is passed to the Stream Pipe Managerthat figures out where to pump the data. This can for example be to the displayor to a local file depending on the set ofconverters registered by the application.*/extern BOOL HTLoadAbsolute (const char * url, HTRequest * request);/*(  Load a Document from Relative URI)Request a document referenced by a relative URI. The relative URIis made absolute by resolving it relative to the address of the 'base'anchor.*/extern BOOL HTLoadRelative (const char * 	relative,			    HTParentAnchor *	base,			    HTRequest *		request);/*(  Load a Document into Memory)Request a document referred to by the URI and load it into aHTChunk object. A chunkobject is a dynamic string so in the end you will have a single memorybuffer containing the document. The chunk must be freed by the caller.*/extern HTChunk * HTLoadToChunk (const char * url, HTRequest * request);/*(  Load a Document and Save as a Local File)This function loads a URI and saves the contents in the specifed file. Thefile should not  be open, as the load function both opens and closesthe file. If the file already exists then it asks the user whether the fileshould be overwritten or not. the contents is saved ASIS - that is- we do not touch the contents of the file!*/extern BOOL HTLoadToFile (const char * url, HTRequest * request,			  const char * filename);/*(  Load a Document and put the Contents into a Stream)Request a document referenced by an absolute URI and sending the data downa stream. This stream can be anny stream you like, for eample one from theStream Interface.*/extern BOOL HTLoadToStream (const char * url, HTStream * output,			    HTRequest * request);/*(  Load a Document using an Anchor)Here the URI is represented by an Anchor object.You can get an anchor object representing a URI by passing the URI to theappropriate method in the Anchor class.*/extern BOOL HTLoadAnchor (HTAnchor * anchor, HTRequest * request);/*(  Load a Document into Memory using an Anchor)This is the same as HTLoadToChunk but instead of passing a URIstring you pass an HTAnchor object. Internally,all URIs are represented as anchors which contains all the information wehave about the resource. The chunk must be freed by the caller.*/extern HTChunk * HTLoadAnchorToChunk (HTAnchor * anchor, HTRequest * request);/*(  Recursively Request a Document using Anchors)Same as HTLoadAnchor() but the information in theerror stack in the requestobject is kept, so that any error messages in one. This function is almostidentical to HTLoadAnchor, but it doesn't clear the error stackso that the information in there is kept.*/extern BOOL HTLoadAnchorRecursive (HTAnchor * anchor, HTRequest * request);/*.  Load Special Documents.We also have a set of functions for loading special files like rules fileswhich also are referenced by a URI but which do have to be treated specially.(  Load a Rule File)Rule files can be loaded just like any other URI but you can also just usethese functions which do all the work for you: they load a rule find withthe URI specified and add the set of rules to the existing set.They come in two flavours - one that asks the user whether it is OK to addthe rules and one that does it automatically without asking. As the app wouldhave to call this method explicitly, it may have other ways of protectingthe user.Both functions use preemptive requestsso that everything else stops in the meantime.*/extern BOOL HTLoadRules (const char * url);extern BOOL HTLoadRulesAutomatically (const char * url);/*.  Search a Document (Method = GET).The search methods all use GET as the method in theHTTP request. The functions takethe keywords and encode them according toRFC1866 (Hypertext Markup language). That is, the query part is separatedfrom the rest of the URI by a "?".The keywords are passed to the function as a ChunkObject and each keyword must be separated by a space ' '. Thiswill then be converted into a '+' before added to the URI.(  Search a Document from Absolute URI)*/extern BOOL HTSearchAbsolute (HTChunk *		keywords,			      const char *	base,			      HTRequest *	request);/*(  Search a Document from Relative URI)Search a document referenced by a relative URI. The relative URI ismade absolute by resolving it relative to the address of the 'base'anchor.*/extern BOOL HTSearchRelative (HTChunk *		keywords,			      const char * 	relative,			      HTParentAnchor *	base,			      HTRequest *	request);/*(  Search a Document using an Anchor)*/extern BOOL HTSearchAnchor (HTChunk *		keywords,			    HTAnchor *		anchor,			    HTRequest * 	request);/*(  Search a Document using an Anchor Using a String)This works exactly as the HTSearchAnchor() function but takesa C string instead of a chunk object.*/extern BOOL HTSearchString (const char *	keywords,			    HTAnchor *		anchor,			    HTRequest * 	request);/*.  Submit Forms Using GET Method.Formdata can be sent to an HTTP server in two ways - it can either use aGET method or it can use a POST method. The differenceis whether the request "has side effects" or not. For example, if you areordering a pizza then the (hopefully positive) sideeffect is that you actuallyget one delivered. However, if you are issuing search data - for exampleto Alta Vista, then there is no sideeffect. In the former example you woulduse the GET form and in the latter you would use thePOST form.(  Submit Form from Absolute URI using GET)Submit formdata using GET to the address indicated as the "base" which mustbe an absolute URI. The list of form data must be given as anassociation list where the name is the field nameand the value is the value of the field.*/extern BOOL HTGetFormAbsolute (HTAssocList *	formdata,			       const char *	base,			       HTRequest *	request);/*(  Submit Form from Relative URI using GET)Submit formdata using GET to the address indicated relative to the addressof the base anchor. The list of form data must be given as anassociation list where the name is the field nameand the value is the value of the field.*/extern BOOL HTGetFormRelative (HTAssocList * 	formdata,			       const char * 	relative,			       HTParentAnchor *	base,			       HTRequest *	request);/*(  Send a Form using an Anchor and the GET Method)Submit formdata using GET to the address indicated of the anchor. The listof form data must be given as an association listwhere the name is the field name and the value is the value of the field.*/extern BOOL HTGetFormAnchor (HTAssocList *	formdata,			     HTAnchor *		anchor,			     HTRequest * 	request);/*.  Submit Forms Using POST Method.The data in a POST form is sent as the body part of theHTTP message whereas aGET form wraps it all up into the URI. In order to be able touse the POST data object at a later point in time, we createa new anchor on the fly. This anchor has a URI file location which pointsinto the temporary area given by the User ProfileObject. That is - you can actually save the anchor using aPUT request and then be able to retrive the form data at a laterpoint in time. Even though this may seem "ambitious" for posting form data,it is really just a special example of sending any kind of data to a remoteserver. All POST form functions return the new anchor orNULL if they fail.(  Submit Form from Absolute URI using POST)Submit formdata using POST to the address indicated as the "base" which mustbe an absolute URI. The list of form data must be given as anassociation list where the name is the field nameand the value is the value of the field.*/extern HTParentAnchor * HTPostFormAbsolute (HTAssocList *	formdata,					    const char *	base,					    HTRequest *	request);/*(  Submit Form from a Relative URI using GET)Submit formdata using POST to the address indicated relative to the addressof the base anchor. The list of form data must be given as an associationlist where the name is the field name and the value is the value of the field.*/extern HTParentAnchor * HTPostFormRelative (HTAssocList * 	formdata,					    const char * 	relative,					    HTParentAnchor *	base,					    HTRequest *		request);/*(  Submit Form using an Anchor and the POST Method)Submit formdata using POST to the address indicated of the anchor. The listof form data must be given as an association listwhere the name is the field name and the value is the value of the field.*/extern HTParentAnchor * HTPostFormAnchor (HTAssocList *	formdata,					  HTAnchor *	anchor,					  HTRequest * 	request);/*(  Submit Form and Save the Result in a Memory Buffer)Submit formdata to the address referred to by theHTAnchor object and load the result of the POSTinto a HTChunk object. Achunk object is a dynamic memory buffer so inthe end you will have a single memory buffer containing the document. Thechunk must be freed by the caller.*/extern HTChunk * HTPostFormAnchorToChunk (HTAssocList * formdata,                                          HTAnchor *    anchor,                                          HTRequest *   request);/*.  Get Metainformation about a Document (Method = HEAD).If you are not interested in the document itself but only in themetainformation that describes the document then you shoulduse the HEAD method in your request.(  Get Metainformation about a Document from Absolute URI)Request metainfomration about a document referencd by an absoluteURI.*/extern BOOL HTHeadAbsolute (const char * url, HTRequest * request);/*(  Get Metainformation about a Document from Relative URI)Request metainformation about a document referenced by a relativeURI.*/extern BOOL HTHeadRelative (const char * 	relative,			    HTParentAnchor *	base,			    HTRequest *		request);/*(  Get Metainformation about a Document using an Anchor)Here the URI is represented by an Anchor object.You can get an anchor object representing a URI by passing the URI to theapproproiate method in the Anchor class.*/extern BOOL HTHeadAnchor (HTAnchor * anchor, HTRequest * request);/*